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Excerpt
This assumption is true but does not take into account the following considerations: (1) when a maximal reduction of diastolic blood pressure (DBP) has been obtained as in the HOT study, it is very difficult to decrease more systolic blood pressure (SBP) without any further reduction of DBP (it is possible but is it a goal to achieve?) (2) Some therapeutic trials have been already performed in order to normalize both SBP (< 140 mmHg) and DBP (< 90 mmHg) [2–4]. In such trial, a high proportion of patients (close to 30%) did not achieve a reduction of SBP < 140 mmHg, as recently emphasized by Black [5]. Furthermore, it is important to recall that, till recent years, all the dose–response curves performed with antihypertensive agents have been based on DBP (and therefore poorly done in the elderly) and that titration of drugs on the basis of SBP has never been achieved, particularly in the elderly [6].
In the study of Zanchetti et al. [1], the authors detailed the subgroups in which, for the same decrease of DBP, SBP remained higher as the corresponding comparator. These groups involved older subjects, mostly women, and were mainly observed in patients with diabetes and/or ischemic heart disease. All these populations with higher SBP [and hence pulse pressure (PP)] are also known to be characterized by a substantial increase of arterial stiffness (see review by [7]). Thus, the question is raised to know whether these subjects, characterized by a higher SBP, PP, and arterial stiffness both at baseline and during treatment, do not achieve a significant DBP reduction at the price of a further increase in stiffness. Indeed it is noteworthy that increased stiffness produces at the same time an increase of SBP and a decrease of DBP [8]. Finally, it is important to evaluate nowadays whether the use of drugs reducing large artery stiffness rather than decreasing vascular resistance (arterioles) should not be appropriate for such categories of hypertensive patients [9].
In the literature, there are three different pathways in which double-blind studies have shown that a selective reduction of SBP over DBP may be obtained in hypertensive subjects through significant and selective alterations of arterial stiffness and wave reflections. First, in old subjects with isolated systolic hypertension, the nitrate derivative isosorbid dinitrate was shown to reduce selectively SBP without reducing DBP and without tachyphylaxia [10,11]. Second, in hypertensive subjects with either systolic–diastolic or isolated systolic hypertension, the low dose combination of perindopril plus indapamide has been shown to reduce more SBP than atenolol for the same reduction of DBP [12]. Finally, in older (> 65 years) subjects with systolic hypertension, the addition to conventional antihypertensive drug therapy of the cross-linking collagen agent aminoguanidine has been demonstrated to reduce selectively SBP and PP without change of mean arterial pressure [13,14].
